In the prior art application specific radar sensors are known for remotely monitoring the health condition of human beings. For example, patent application GB2349759 discloses a device for monitoring a heartbeat comprising a radar adapted to detect a beam of microwave radiation towards a living body whose heartbeat is to be monitored, and to derive a phase-shift signal representative of the phase-shift between a transmitted signal and a reflected signal, a controllable filter to filter the phase-shift signal and to pass a frequency spectrum anticipated to contain signals corresponding to the heartbeat to be monitored, an output of the filter being passed to a spectral analysis unit to conduct a spectral analysis to isolate the signals representative of the heartbeat, the spectral analysis unit being adapted to control the filter by reducing the pass-band width of the filter and selecting the pass-band frequency range so that the filter passes the signals corresponding to the heartbeat, the arrangement providing an output signal representative of the heartbeat being monitored.
Preferably the phase-shift signal is passed through analogue-to-digital converter, and the filter is a digital filter. The output signal representative of the heartbeat can be monitored and an alarm signal may be generated if the monitored signal meets predetermined criteria.The alarm is associated with additional sensor means adapted to sense a parameter indicative of the approach of sleep to the person whose heartbeat is being monitored. The radar incorporates an antenna, the antenna being located in part of a support for the body whose heartbeat is to be monitored to direct said beam of microwave radiation towards the body supported by the support.
Patent application US2013053653 discloses a system for non-contact monitoring of a subject. The system includes one or more range-controlled radars configured to transmit a radar signal and receive a reflected radar signal from the subject in a resting state. Further, the system also includes at least one processing unit communicatively coupled to the one or more range-controlled radars. The processing unit is configured to non-invasively detect one or more motion and/or physiological parameters corresponding to the subject using the one or more range-controlled radars. The motion parameters comprise one or more activity levels and the physiological parameters comprise one or more of heartbeat and respiration. The processing unit determines one or more patterns in the motion parameters detected over a designated motion period of time. Additionally, the processing unit determines one or more patterns in the physiological parameters detected over the designated physiological period of time. The processing unit then assesses a health condition of the subject based on the determined patterns of the motion parameters and/or the determined patterns of the physiological parameters. The system further includes a data repository coupled to the processing unit to store one or more of the reflected radar signal data, the motion parameters, the physiological parameters and/or the determined patterns.
The prior art sensors are limited to a specific application based on a predefined sensor type and are inflexible with regards to multi-application use scenarios for said sensors. Further such sensors have powerful on-board computing resources to locally perform the data processing according to the application logic. Such complex data processing is typically associated with increased energy consumption of the devices.